This invention relates to laryngeal mask assemblies.
It is common practice to use an airway known as a laryngeal mask for the administration of anaesthetic and ventilation gases to a patient. These airways comprise a tube with an inflatable mask or cuff at one end, the tube being inserted in the patient's mouth so that one end is located in the hypopharynx and so that the mask forms a seal in this region with the surrounding tissue. Laryngeal masks are described in, for example, U.S. Pat. No. 5,355,879, U.S. Pat. No. 5,305,743, U.S. Pat. No. 5,297,547, U.S. Pat. No. 5,282,464, GB 2267034, U.S. Pat. No. 5,249,571, U.S. Pat. No. 5,241,956, U.S. Pat. No. 5,303,697, GB 2249959, GB 2111394, EP 448878, U.S. Pat. No. 4,995,388, GB 2205499, GB 2128561 and GB22988797.
Laryngeal masks have several advantages over endotracheal tubes, which are longer and seal with the trachea below the vocal folds. One problem with laryngeal mask airways, however, is that it is difficult to provide the cuff, which is of relatively complex shape, at low cost.